Ball mill or the like



Jan, 3, 1967 T. w. CUNNINGHAM 3,295,772

BALL MILL OR THE LIKE 2 Sheets-Sheet 1 Filed Dec. 22, 1964 INVENTOR, THOMAS w. CUNNlNGFHAM ATTORNEY Jan. 3, 1967 T. w. CUNNINGHAM 3,295,772

BALL MILL OR THE LIKE Filed Dec. 22, 1964 2 Sheets-Sheet 2 FIG. 4

l INVENTOR l/ THOMAS W. CUNNINGHAM 004% 6. Mac

ATTORNEY United States Patent Ofifi ce 3 ,295,772 Patented Jan. 3, 1967 3,295,772 BALL MILL OR THE LIKE Thomas W. Cunningham, Uniontown, Ohio, assignor, by

mesne assignments, to US. Stoneware, Inc., a corporation of Massachusetts Filed Dec. 22, 1964, Ser. No. 420,337 Claims. (Cl. 241-182) This invention relates to a ball mill or a rod mill or the like, the chamber of which is lined, at least partially, with resilient blocks.

The mill chamber, which is generally cylindrical, is made with a shell (jacketed or not) in which are spaced rods which are parallel to the surface of the shell. The blocks are made of rubber, polyethylene, polypropylene, polyurethane or other resilient material. Openings are provided in each block which are parallel to that surface of the block which is to be exposed to the interior of the mill. In most blocks, these openings will extend from one edge of the block to the opposite edge. However, such openings in those blocks which are used at an edge of the lining, for instance those used around an opening in the shell, may extend only part of the way through the block so that the side of the block which is exposed at the opening has no hole in it. Also, for short rods, such as T-bars adapted to hold a single block, each end of the opening may be spaced inward from the respective walls of the block.

These openings are referred to herein as the rod openings. They diverge from a narrower slot in the portion of the opening which is to hold the rod, to a wider slot at that surface of the block which is to be adjacent the shell. The blocks are installed in the chamber, one by one, by positioning the rod opening over one of the rods, and then by applying pressure to the block forcing the rod into the opening. The blocks are sufficiently resilient to permit them to be snapped into place. If the sides of the blocks are smooth, the blocks may be removed from time to time for replacement for any reason. However, the sides are not necessarily smooth but may be provided with tongues and grooves and interlocked, and then replacement may be diflicult.

Usually, cross rods which are supported parallel to the circumferential inner surface of the shell, are provided under the aforementioned rods which are parallel to the longitudinal surface of the shell. They give the axial or longitudinal rods support. These circumferential rods may be relatively close together or spaced farther apart. Cross openings are provided in some or all of the blocks to accommodate these.

In addition, there may be post openings in some of the blocks. If the rods are merely T-bars, there must be a post opening in each block. If the ends of the axial rods are fastened in the ends of the mill, there are no post rods and no need for such openings. There are various ways of supporting the axial rods which will make it necessary to provide post openings in the blocks. For instance, the axial rods may be supported by posts located intermediate their ends, and in such a construction the circumferential supporting rods may not be necessary. Instead of attaching the ends of the axial rods to the ends of the mill, their ends may be bent over to form post supports which are fastened to the shell. Post openings will be required in blocks to accommodate these. The ends of the axial rods which are in line with the opening in the shell may be supported in the same way, and post openings will be required to support these. If there are post openings in all of the blocks and only some of them are used to accommodate posts, their presence in the other blocks does no harm.

The resilient lining formed from the blocks may cover the entire inner surface of the mill, or it may cover only the cylindrical surface or any other limited area. The inner surface of the dOOr of the mill may be covered with resilient blocks, but this is not essential. It may be provided with a different type of resilient cover. The ends of the interior of the mill are usually fiat and may each be covered with sheet lining.

The invention is further described in connection with the accompanying drawings, in which:

FIGURE 1 is a view in perspective of the mill with the door open and with parts of the mill broken away to show the interior construction;

FIGURE 2 is a view in perspective of an individual block with parallel walls;

FIGURE 2a is a view in perspective of a modification in which the rod opening extends only part-way through the block and joins the post opening;

FIGURE 3 is a view in perspective of a block with a tongue in one wall and a complementary groove in the opposite wall;

FIGURE 4 is a section on the line 4-4 of FIGURE 1 through the top and one end wall of the mill;

FIGURE 5 is a section on the line 5-5 of FIGURE 1 through the end wall of the mill; and

FIGURE 6 is a section on the line 6-6 through the cylindrical wall and the door of the mill.

The shell of the mill shown in the drawings is formed of an outer steel wall 5 and an inner steel wall 6 which are spaced by strengthening ribs 7 to form a jacket for cooling the contents of the mill. Such a jacket is optional. The end wall is formed of a single steel sheet 9. The end walls may be of any other suitable construction. Small round rods 10 are arranged parallel to the axis of the mill and spaced a short distance from the inner cylindrical Wall 6. They are spaced uniformly from one another. The ends of these rods 10 are welded in the plates 9 at the ends of the chamber, as shown most clearly in FIG URE 5. Alternatively, the ends may be bent and welded to the inner circumferential wall 6. The rods having inner ends which terminate at the opening are advantageously bent in this way and fastened to the circumferential wall.

The portions which are perpendicular to the wall 6 are called posts and identified by the numeral 12. Other rods 14 supported from the wall 6 and perpendicular to rods 10, are located immediately under the rods 10 and support rods 10 so that when the mill is in operation the balls or rods or other grinding media pounding against the inner surface of the mill do not deflect the rods 10 toward the wall 6.

The blocks of FIGURE 2 with parallel walls 16 may be sufficiently resilient to be forced into abutting relation with one another, or blocks with tapering walls 17 (FIG URE 3) may be used, as in smaller mills. The blocks may be made interlocking with tongues 18 and grooves 19 as shown in FIGURE 3, but ordinary smooth-walled blocks, as shown in FIGURE 2, will be quite satisfactory.

Rod openings 22 usually extend through the blocks from one end to the other, but these openings may be shorter, as explained. The openings 23 diverge from these openings to the bottoms of the blocks. These blocks are installed by slipping the opening 23 of each block over one of the rods 10 and then pushing the block into place. Adjacent blocks are usually in pressure contact on all sides so that the material being ground does not collect between the blocks, but this is not essential. Immediately adjacent the portions 22 of the openings which accommodate the rods 10, the openings 23 are narrower than at the bottom of the blocks, and they are narrower than the rods so that the blocks clamp themselves in place. Notches 25 are provided, in at least some of the blocks, to straddle the rods 14, where such supporting rods are employed.

The rod opening 27 in the block shown in FIGURE 2a accommodates a rod 10, and the post opening 28 in the slot in the inner portion of the rod and extending to the surface of the block accommodates its bent-over end 12.

The inner surfaces of the ends of the mill may be covered by sheet material adhered in the usual manner, or they may be covered with blocks as shown in FIGURE 5. This figure clearly shows rods 30 which are evenly spaced and are parallel to the end walls, and the rods 31 which support these to prevent deflection of them towards the respective walls. The rods 30 are shown as being sup ported by their ends being bent at substantially right angles to form posts which are welded to the end walls. Instead of bending the ends of the rods 30, they might terminate abruptly and be supported near their ends by short posts.

The rods 10 and 30 may be spaced from their respective walls at intervals, by short posts, making the cross rods 14 and 31 unnecessary.

The mill illustrated in the drawings includes an opening provided with a door closure 40 which is hinged at 41, and may be fastened shut by winged nuts 43 or other suitable fastening means. In the drawing, the inner surface of the door 40 is an arched shell 45 over which are spaced parallel rods 47 supported by rods 48. The ends of rods 47 and 48 are bent over to form posts which support these rods away from the shell 45. Blocks with post openings are snapped over these rods and cover the inner surface of this door. A door of more usual construction with any appropriate lining may replace the door shown here.

The mill is mounted in any usual manner and driven by usual means. Often, only the cylindrical wall is covered with resilient blocks. It is not as necessary to cover the end walls because they are not subjected to the constant pounding that the cylindrical wall receives.

The composition of the blocks will be selected to prevent interaction between them and the material to be ground. The modulus of the blocks will depend upon the weight of the grinding media, the size of the mill, and the nature of the grinding operation.

The invention is covered in the claims which follow.

What I claim is:

1. A mill with a grinding chamber therein, an area of the inner surface of which chamber is provided with a rod which is supported parallel to said surface and covered by resilient blocks snapped over the rod.

2. A mill having a grinding chamber with its inner surface covered, at least partially, with a lining of resilient blocks, spaced rods within the chamber which are parallel to an inner surface of said shell, each of said blocks being provided with a rod opening to accommodate one of said rods in a portion thereof, a longitudinal slot in said portion of the opening which is narrower than the rod, the opening diverging from said slot to a wider slot in the surface of the block adjacent said inner surface of the mill, the blocks being sufficiently resilient so that the diverging portion of the rod opening can be spread to snap over a rod when in position in the opening, and each block being thereby held in place.

3. The mill chamber of claim 2 with a cylindrical wall which is entirely covered with resilient blocks.

4. The mill of claim 2 in which at least one of the rods is supported by posts, and blocks located at the posts are provided with openings to accommodate the posts.

5. A liner block for a mill which is composed of resilient material and provided with parallel inner and outer surfaces, a rod opening in the block with an inner portion designed to accommodate a rod, said opening diverging from a longitudinal slot in said inner portion to a wider slot in said outer surface.

6. A liner block of claim 5 which includes an opening in said longitudinal slot to accommodate a post which is perpendicular to said rod opening.

7. A liner block of claim 5 in which a post opening extends from said outer surface substantially perpendicular thereto, and connects with said rod opening.

8. A liner block of claim 5 in which the rod opening extends from one wall of the block to the opposite wall.

9. A block of claim 5 in which one end of the rod opening stops short of a wall of the block to which the opening is perpendicular.

10. A block of claim 7 in Which one end of the rod opening terminates in the post opening.

No references cited.

WILLIAM W. DYER, JR., Primary Examiner.

G. A. DOST, Examiner. 

1. A MILL WITH A GRINDING CHAMBER THEREIN, AN AREA OF THE INNER SURFACE OF WHICH CHAMBER IS PROVIDED WITH A ROD WHICH IS SUPPORTED PARALLEL TO SAID SURFACE AND COVERED BY RESILIENT BLOCKS SNAPPED OVER THE ROD. 